The invention is directed to a sensor for use in the warhead of a missile launched for an attack on a helicopter positioned on or near the ground surface.
An active optical sensor is known for discriminating enemy targets from surrounding objects. Such an active optical sensor is capable of differentiating helicopters, vehicles, tanks etc. from ground and ground vegetation and triggering an ignition accordingly. This is achieved in that the tramsmitter beam, as well as the receiver beam, is bundled in the centimeter or millimeter range and the time resolution lies in the nanosecond range or the target surface is scanned with a high repetition frequency.
This known sensor, while having been tried and proven effective, is, however, for so-called approach sensors for use in warheads of missiles specifically targeted against helicopters and is generally unsuitable for use as its costs are far too expensive.
The present invention is based on the task of creating a sensor of the initially mentioned kind, with which a missile, for example, a grenade, can be used for attack on a helicopter, detected on or near ground level, without the sensor responding to other apparent targets such as trees, bushes, rocks, huts, etc. Generally, the present invention includes a sensor in a warhead of a missile, which sensor comprises at least one high-resolution laser range finder (LRF) which is inclined forward in the direction of flight and one evaluation circuit which includes a clock and a processor. The LRF is operable to direct signals forwardly of the missile. The signals scattered back to the sensor by the rotor blades of the helicopter are compared by the processor to "velocity/flying time profile" data and reference pattern data. The data comparison, together with a measurement of time elapsed since the launching of the missile, enables the processor to determine the presence, direction, range, position and type of helicopter and to activate an ignition accordingly.